Elizabeth Holmes, 31 Founder of blood-testing company Theranos Net worth: $4.5 billion http://www.marketwatch.com/story/10-wealthiest-people-in-the-world-under-40-2015-03-04?page=2 From Forbes #360 Elizabeth Holmes Real Time Net Worth As of 3/4/15 $4.6 Billion Age 31 Source Of Wealth blood testing, Self Made Self-Made Score 8 Residence Palo Alto, CA Citizenship United States Marital Status Single Education Drop Out, Stanford University At 31, Elizabeth Holmes makes her debut on the Billionaires list as the youngest self-made woman billionaire. She dropped out her sophomore year of Stanford University to found Palo Alto, Calif.-based blood testing company Theranos in 2003 with money she saved for college. With a painless prick, her labs can quickly test a drop of blood at a fraction of the price of commercial labs which need more than one vial. Theranos has raised $400 million from venture capitalists, valuing the company at $9 billion, and Holmes' 50% stake at $4.5 billion. She has assembled a stellar board that includes elder statesmen George Shultz and Henry Kissinger. In 2013, Walgreens, the largest U.S. retail pharmacy chain, with more than 8,100 stores, announced plans to roll out Theranos Wellness Centers inside its pharmacies.